Because radio frequency (RF) signals are received in the analog domain, wireless communication systems often use Analog-to-Digital Converters (ADC) to convert the received RF signals to digital information. Analog signals, such as RF signals, modulated on an optical carrier are difficult to encrypt without digitizing the information. To encrypt an analog signal, the analog signal is generally first digitized using an ADC and then the information is remodulated on an optical carrier. However, this requires moving the information from the optical domain to the electrical domain, and then back to the optical domain, adding complexity to the overall system and increasing its size, weight, and power (SWaP). Furthermore, decrypting digitally encrypted information having a large number of samples requires a computer with significant processing power.